Seasonality and spatial variability of dynamic precipitation controls on the Tibetan Plateau
Seasonality and spatial variability of dynamic precipitation controls on the Tibetan Plateau
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DOI：
10.5194/esd-7-767-2016
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发表时间：
2016-09-20
影响因子：
7.3
通讯作者：
Scherer, Dieter
中科院分区：
文献类型：
--
作者：
Curio, Julia;Scherer, Dieter
青藏高原是亚洲许多大河的发源地，为南亚和东亚广大地区提供水资源。因此，青藏高原及其邻近高山区的水循环，尤其是降水的分布和变率，对青藏高原下游数十亿人口的水资源供应起着重要作用。本文采用高亚洲精细分析（HAR）方法，分析了影响青藏高原及其邻近高山区降水变率的动力因素，包括导致降水增、抑的因素。考虑了影响降水的4个动力场：300 hPa风速和2km高空风速、300 hPa垂直风速和大气水汽输送。研究的重点是降水控制的季节性和空间变异性及其主导模式。结果表明，不同地区、不同季节，不同因子对降水的影响不同。这主要取决于降水的主要类型，即对流或锋面/气旋降水。此外，研究还表明，中纬度西风带对TP及其周围地区的降水分布有很大的影响，而不仅仅是在冬季。
The Tibetan Plateau (TP) is the origin of many large Asian rivers, which provide water resources for large regions in south and east Asia. Therefore, the water cycle on the TP and adjacent high mountain ranges, in particular the precipitation distribution and variability play an important role for the water availability for billions of people in the downstream regions of the TP.The High Asia Refined analysis (HAR) is used to analyse the dynamical factors that influence precipitation variability in the TP region, including the factors resulting in the enhancement and suppression of precipitation. Four dynamical fields that can influence precipitation are considered: the 300hPa wind speed and wind speed 2km above ground, the 300hPa vertical wind speed, and the atmospheric water transport. The study focusses on the seasonality and the spatial variability of the precipitation controls and their dominant patterns. Results show that different factors have different effects on precipitation in different regions and seasons. This depends mainly on the dominant type of precipitation, i.e. convective or frontal/cyclonic precipitation. Additionally, the study reveals that the midlatitude westerlies have a high impact on the precipitation distribution on the TP and its surroundings year-round and not only in winter.